1.Lub hauv paus yog dab tsi?
Cov hlau muaj lub cev -centered cubic crystal qauv. Nyob rau hauv cov qauv no, lub peev xwm ntawm dislocations txav ntawm atoms txo qis vim qhov kub thiab txias.
Thaum qhov kub thiab txias poob qis dua tus nqi tseem ceeb (hu ua ductile -kho qhov hloov pauv kub), cov khoom hloov pauv ntawm cov pob txha tawg (nrog rau cov yas deformation tseem ceeb) mus rau pob txha tawg (nruab puas ntsoog nrog yuav luag tsis muaj cov yas deformation).
2.Dab tsi yog qhov exacerbating los ntawm cov txheej txheem txias dov?
Ua hauj lwm hardening: Txias dov yog txheej txheem yas deformation nyob rau hauv chav tsev kub, uas ua rau grain distortion thiab muaj zog dislocation ceev, yog li txhim kho lub zog thiab hardness ntawm cov khoom, tab sis txo plasticity thiab toughness. Qhov no tsis tshua muaj plasticity xeev ua phem ntxiv nyob rau qhov kub thiab txias.
Kev ntxhov siab sab hauv: Cov txheej txheem txias dov tawm qhov kev ntxhov siab tseem ceeb hauv cov khoom, uas tuaj yeem txhawb kev pib tawg thiab nthuav tawm ntawm qhov kub qis.
3.Dab tsi yog qhov tseem ceeb cuam tshuam?
Tshuaj muaj pes tsawg leeg:
Cov ntsiab lus carbon: Cov ntsiab lus carbon ntau dua feem ntau ua rau cov khoom siv hluav taws xob ntau dua - qhov kub thiab txias hloov tau ntau dua thiab hais tau qis dua - kub brittleness.
Impurity Elements: Cov ntsiab lus impurity xws li phosphorus, sulfur, thiab nitrogen ua rau kom txias brittleness nyiam ntawm hlau.
Alloying Elements: Ntxiv cov khoom xws li npib tsib xee thiab manganese tuaj yeem ua kom zoo dua cov nplej loj, txo cov ductile -nkig hloov kub, thiab txhim kho qis - kub toughness.
Microstructure:
Grain Size: Cov nplej zoo tuaj yeem txhim kho cov tawv nqaij thiab txo qis dua -qhov kub hloov pauv hloov. Recrystallization annealing tom qab txias dov tuaj yeem txhim kho toughness.
Microstructure Hom: Ferritic steels qhia tau hais tias qis dua - kub brittleness, thaum austenitic stainless hlau (xws li 304), vim lawv lub ntsej muag -centered cubic qauv, feem ntau tuav zoo toughness ntawm qis kub.
Kev Pabcuam Kub: Qhov ntsuas kub qis dua, qhov hnyav dua qhov txo qhov tawv. Cov qib sib txawv ntawm cov hlau muaj lawv qhov tshwj xeeb yam tsawg kawg nkaus kev pabcuam kub.
4.Dab tsi yog qee qhov kev tiv thaiv hauv kev siv engineering?
Kev xaiv cov khoom: Hauv qhov qis- qhov kub thiab txias (xws li cov qauv sab nraum zoov hauv cov cheeb tsam txias, cov hlab ntsha cryogenic, thiab cov khoom siv thauj mus los), yuav tsum xaiv cov hlau cryogenic.
Piv txwv li, Q345D/E (raws li qub qib 16MnDR) yog qis- alloy siab- lub zog steel. Qhov "D" thiab "E" nyob rau hauv qib kev xaiv sawv cev rau cov kev cuam tshuam toughness ntawm -20℃thiab -40 degree, feem.
Rau ib puag ncig cryogenic (xws li cov khoom siv roj ntsha liquefied), austenitic stainless hlau lossis npib tsib xee alloys yuav tsum tau.
Kev kho cua sov: Annealing txias-khoov hlau tuaj yeem tshem tawm kev ua haujlwm tawv thiab rov ua kom cov yas thiab tawv.
Tsim thiab tsim khoom: Zam tsis txhob muaj qhov tob tob thiab qhov kev ntxhov siab, tswj cov txheej txheem vuam nruj me ntsis (kom tiv thaiv kom tsis txhob muaj cua sov- cuam tshuam rau cheeb tsam embrittlement), thiab ua qhov kev ntsuas kub tsawg los xyuas kom muaj kev nyab xeeb.
5.Qhov txias txias npaum li cas - dov kauj nyob rau hauv qhov chaw qis - kub?
Vim nws cov yam ntxwv ua, txias- dov coils inherently muaj qis toughness dua kub- dov los yog annealed coils. Qhov no txo qis hauv toughness (nce brittleness) yog ntau tshaj tawm ntawm qhov kub thiab txias. Yog li ntawd, thaum siv txias- dov steel hauv qis- qhov kub thiab txias, kev xaiv cov khoom yuav tsum tsis txhob ua raws li nws chav tsev xwb - qhov kub thiab txias. Nws cov ductile-kub hloov pauv hloov pauv yuav tsum tau txiav txim siab tag nrho, thiab cov ntaub ntawv ua tau raws li cov qauv qis-kub toughness yuav tsum raug xaiv. Kev kho cua sov yuav tsim nyog los txhim kho kev ua haujlwm. Hauv kev siv cov tswv yim, qhov yuav tsum tau ua rau qis - qhov kub thiab txias ntawm cov khoom siv hauv cov qauv kev lag luam thiab cov kev qhia tshwj xeeb (xws li GB / T 150 "Pressure Vessels", EN 10028, thiab lwm yam) yuav tsum ua raws li nruj me ntsis.